Why is .22 CB Short louder than .22 CB Long in my rifles?

[hminsky]

I have some .22 CCI CB Short ammo, and some of the CB Long. The Short and Long specs say they both have the same weight bullet and and same velocity, only difference is length of the case, but when I shoot in my rifles (pump 1906 winchester, and various single shot and bolt action), the CB Short are a lot louder. Anyone know why this might be?

 

[drgrant]

I have some .22 CCI CB Short ammo, and some of the CB Long. The Short and Long specs say they both have the same weight bullet and and same velocity, only difference is length of the case, but when I shoot in my rifles (pump 1906 winchester, and various single shot and bolt action), the CB Short are a lot louder. Anyone know why this might be?

Maybe the burn rates of the powders used are different?

Also it says there the same but do we know? Like i never assume something is the same without popping it over a chrono. You can be surprised..... in either direction.

 

[jkelly1229]

Trumps fault

 

[pupchow]

Maybe the short case isn't fully supported in the chamber, and it passes gas?

 

[HARRYM]

Pressure related.

 

[hminsky]

Maybe the burn rates of the powders used are different?

Also it says there the same but do we know? Like i never assume something is the same without popping it over a chrono. You can be surprised..... in either direction.

I was wondering if it might be something to do with the chamber. If the gun can shoot 22 LR, L or S, doesn't that mean there is some more open space in front of the bullet when you chamber a short, before it gets inside the throat of the barrel? So maybe the hot gas leaks out back towards the bolt when the end of the case is far from the throat? So maybe the noise is coming from the chamber and not the end of the barrel?
I've never really understood how the rifles can handle all three cartridge lengths.

 

[Uzi2]

I was wondering if it might be something to do with the chamber. If the gun can shoot 22 LR, L or S, doesn't that mean there is some more open space in front of the bullet when you chamber a short, before it gets inside the throat of the barrel? So maybe the hot gas leaks out back towards the bolt when the end of the case is far from the throat? So maybe the noise is coming from the chamber and not the end of the barrel?
I've never really understood how the rifles can handle all three cartridge lengths.

Well, one reason is they all headspace on their rim, like being able to shoot .38spl in a357mag and .44spl in a .44mag.

The .22LR chamber will accommodate and fire the shorter ammo, but not vice versa.

The beginning of the rifling (throat) would have to be forward of the longest of the 3 so the longer cartridge wouldn't jam into the rifling. Guns made for shorts will not chamber longs or long rifle ammo.

The other thing is the actions of the multi capable guns. Some actions that are .22LR only will not function using shorter length ammo but they will all fire the shorter length ammo if fed by hand.

 

[StevieP]

My first thought was the burn rate, too. if the shorts use a slower burning powder it's not exploding in the chamber. some of the unburnt powder exits the muzzle with the projectile, where it explodes when it hits oxygen.

er sumpin...

 

[alx]

As mentioned- pressure related. The smaller case has much less free space inside so pressures are probably -much- higher... resulting in louder explosion when ignited.

 

[hminsky]

As mentioned- pressure related. The smaller case has much less free space inside so pressures are probably -much- higher... resulting in louder explosion when ignited.

I think that makes the most sense...

 

[Bigfudge16]

The reception of sound for the pitch of longs has been damaged in your ears. Huh?!?